Acid milk powder.



L. G. MERRELL.

ACID MILK POWDER.

APPLICATION FILED Nov. 1,1905.

1,000,686, 7 l Patented Aug. 15, 1-911.

. WMA/EK IEWIs'c; or smcusn', Nnw Yonx, Afssreiroiar. 'To MERRELL-sonne cony rm, or 'smcusla NEw'Yonx, A' conroanTIoN or NEw'Yoax.

' acm MILK POWDER.

1,000,686. l. I Application tiled November To allmayconcem: I

'Be it known that I, LEWIS C. MERRELL, of Syracuse, inthe county-of Onondaga, in

I theSt'ate of -New York, have invented new anduseful 'Improvements in Acid vMilk Powder, of which the following, 4.taken in` connection with the accompanying drawings, is' a full, clean-and exact description. This invention rela-tes to the production of an acid milk powder, wholly soluble in water, as a new article of manufacture.

My object: isv ltoyproducean. acid -`milk powder, solublejin waterwh ich is-distinctly acid in' its character and reaction, 'and in which the physical character of the albumen, casein, fat, mineral salts, sugar, lactic acid, enzyms,"and all other nat'uralconstituents remain vthe-same as in the :original acid milk vbefore `desiccatio1 1, as distinct frein-:theu

My furtherfgobjec'tgis', .toproduce an4 impalpable 'acid milk-.powder which is free produced,-

from any -foreign element and which is 25 wholly andV readily soluble in' 'water and capable of complete restoration ,to lts .orlginal liquidcondition pssessing the same vproperties as 'before desiccation.

It .is a weil known fact that. mn; which contains substantially more than .3 of 1% of acid will whey oli' at ordinary temperal ture,.and the curd cannot then be dissolved except -by the addition of `an alkali or other -chemical solvent.- Ifjmilk, which contains substantially more than .15 ofl1% of acid is condensed or dried f s'lowly the acid wil-l combine with the salts in such a way as to render the casein insoluble whenthe 'acid in the condensed milk becomes substantially more than...75v of 1% of the total weight of the c ol'icen'trated` .or partially dried milk. is dried slowly at low .temperature there isan .increase in thetotal weight of the acid, in addition to the increase in the percentage due to concentration. -For the temperatures usually ;em-' ployed in low temperature drying aresuch as to favor the growth of lactic-acid-producing bacteria.

The processes ordinarily employed in drying sour orpartially sour milk are two: One consists of drying slowlylin shallow pans'.- The eiect ofthe lactic acid upon tho Bpecicati'on of Letters Itaccnt.--

1, 1905. serialfno.- 285,438.

I Patented vAugylti, 1911.

The otherprocess consists .of drying the sour or partially sour milk 'vacuo'. If steam 4is used in the vjacket the thickening'l product gradually rises vto the temperatu re of the walls ofthe steam illedV jacket, even 160 though the temperature of the vacuum may be as low as 130 F. with the result'thatthe Acurd in thefinished product is rendered-.in-

soluble in water. If heated water is used acidityof fresh milk froml. rendering the casein of the milk insoluble in water. This' is'due lto the fact that the .acid Vcombines with the salts which hold .the casein in solution and-renders it'insoluble in v the milk 8 0 serum.-

If the casein of the milk 'is to' bekeptisoluble in water, the invariable-practice, heretofore, 'has lbeen'to-neutralize the .lactic acid"- by the introduction of lime or which in excess givesthe milk an alkaline or :soapy taste; changes the character of the casein and fat, and under certain conditions subjects the proteids t0 decomposition so that they in time 'develop -a foul and i111-- 90 savoryodor." r

It is well known that fresh warm milk, as it comes from the cow, contains only avery slight amount ofacid, and thatthe amount of .thisacid grows older in proportion tothetemperaf ture at which vthe milk is kept, owingto 'the action of thelactic acid bacteria.- lvTo produce `a dry -mil'k containing any the milk to stand and retain its animal heat as .long as maybe necessary to produce the amount of acid which is desired as a coni'. stituent or, .the acid may be developed b artilicil f t0 prov ucejany given percentage. o aci in the milk is well known among scientilsllgsl'v salts, in lthis process, renders the curd `in the and appears-in the leading publications, sol

dry powder product -ins0luble water. 55

in the jacket instead-of v'steam-'the drying 65.'

ders is neutralized to. prevent the slight other alkali,

gradually increases, as the milk given amount of lactic acid I first allow heat.- The vlength of time require that it will not be necessaryA to repeat it here. The milk is then vcooled4 at such a l temperature as will'maintain the acidity at alpredetermined degree. By experiment in this direction, I have found that the temperature of 60 F. will preserve milk so acid in the total volume in the liquid in 12 hours. I. also find that a temperature of 54 F. will preserve the percentage of acid practically constant for a-period of 12 hours,

and I-have also found 'that a temperature 'of duce an acid milk powder in which the casein is not rendered insoluble. A

I claim to be the first to have produced such'a product and that is my invention. I do not claim to be the sole inventor of the apparatus by which the acid milk is dried at a low temperature, so rapidly as to avoid increasing the acidity, but I do claim to be the first to discover that by such rapid evaporation or desiccation whereby 'the acidity is not increased, a new productie produced, namely, an acid milk powder whollysoluble in water. The apparatus for such drying is shown in the accompanying drawings and description thereof, in which,-

Figure 1 is a transverse, and Fig. 2 is a longitudinal sectional view of a desiccating apparatus for carrying out the objects stated.

As stated above the 'fresh milk is rst al.

lowed to attain the desired percentage of acidity by the' well known methods, after which it is introduced in a finely divided state into a suitable .desiccating chamber -1- through 'a series of atomizers or spraying nozzles -2-, and this nely divided liquid spray is"caused to commingle with a suitable moisture absorbing medium, such as air or gas, which may be forcibly introduced into the chamber 1 through asuitable inlet Themoistureiabsorbing power of this fluent may be materially increased by first passing it' through a cooler 5,- by means of a fan or blower -6- and then forcing the cooled absorbent, -by the same means, through ajheating chamber -7-'ii'ito the desiccating chamber l--1--, care being taken, ofcourse, to keep the .tem-

perature of the absorbent suc-ienty lollig to.

milk before desiccatioi'i,

prevent any chemical change or denaturali- L zation in powdered milk during thel process of desiccation. This commingling ofthe moisture absorbing air with the finely divided li uid causes 'the former to absorb suspension practically all of theA moisture from the milk, leaving a ine impalpable flour or precipitate whichfalls to the bottom of the chamber --1-', and under the pressure from the fan or blower l-6-- together with the moisture 'laden air is forced upwardly through a vibrating conduit the -lower side of which is provided with acomparatively narrow inlet-slit "--9 and is caused to traverse a concentric bottom -10- of the chamber This desiccated product containing practically all of the acid which was in the original acid milk. at the time of introduction into the chamber --1, but in a more concentrated form, is forced through the conduit -8-' and into a suitable collecting vat -11- having a fine screen in one or more sides to allow the escape of the moisture-laden air to atmosphere, leaving lthe desiccated prod-- uct in'the vat.

As' also the apparatus herein shown and described, forms no part of my present invention, therefore, it is believed to be unthe constituents of the liquid or and to hol in necessary t0 enter into further description l of its structure and operation. In the manufacture of powder, I have, fouird\i by actual test that a liquid skimmed milk treated in the manner hereinbefore'd'escribed so as to contain say, .27% acid, will, when reduced to afowdered condition contain about 3.1% aci mixing this powder with'thesaine-quantity of water, which was in the original liquid it is restored to the same primal conditions possessing the same percentage of acid and other natural properties, including the capability of beiner coagulated as the original acid milk. U I, tlierefore, believe that I have made an important roduce a distinctly acid-milk powder inw ich the percentage .ofacidity may be verified at will from va minimum of say 1.251% to a maximum of, say 3.5% without in any way injuring the natural propertics of, or producin any the liquid or pow ered milkor their constituents, it being found thatv any excess in the percentage of acid Vbeyond .3%. in the liquid milk, tends to curdle the liquid milk, which, of course, would tend to destroy the a solubility of the desiccated product. I As further showing. the utility of my improvedfprocess and its product, itmay be stated that skimmed milk containing say, .29% of acid and desiccated in the' manner described, produces a'iiiiewhite powdercon- 1 this acid milk' and by VVandhighly valuable-discoveryn lthatI Yam the first to chemical change in as the original liquid milk and that this I powder may be restored to the primal -liquid state having the same properties as the liquid ,from which the powder was produced. As a further example, I have desiccated a skimmed milk containing 'about .2 of 1% of acid and have found that the desiccated product contains about 2.25% acid and that this highly acidulated powder is highly useful giving the same result as acid milk and avoiding any cheesy or alkaline iliavor or yellowish tints so commonly produced in bake stuffs, by'neutral or alkaline powders. l l

What I -claim is:`

1. A milk` powder containing lactic acid so soluble in water as to approximate the original acid liquidmilk.

l2. A soluble milk powder containing from 1.25% to 3.5% oflacticacd.

. 3. A n acid milk-powder wholly soluble in Water. Y v E,

In witness whereofv I have hereunto set my hand on this 30th day of October, 1905.

v LEWIS l( )..MERRELL Witnesses:

vJ.- M. HAMMEKEN,

HOWARD I?. DENIsoN. 

